Bicycle-brake.



UNITED STATES PATENT Fries.

CHARLES KNAFFL, OF KNOXVILLE, TENNESSEE, ASSIGNOR OF ONE-THIRD TO HENRY E. MAXVELL, OF SAME PLACE.

BICYCLE-BRAKE.

SPECIFICATION forming part of Letters Application filed March 17, 1896.

To all whom, t may con/cern: Be it known that I, CHARLES KNAFFL, a citizen of the United States, residing at Knoxville, in the county of Knox and State of Ten- 5- nessee, have invented a new and useful Bicycle-Brake, of which the following is a-speciication.

This invention relates to bicycle-brakes; and the object in view is to provide a brake ro which is entirely independent of the tire and arranged in proximity to the hub of the drivingwheel, whereby it is adapt-ed to be 4operated and applied through the medium of the drive-chain and to exert its restraining force I5 upon the said driving-wheel.

Other objects and advantages of the invention will appear in the course of the subjoined description. v

The invention consists in an improved 2o brake forbicycles and vehicles of a similar character embodying certain novel features and details of construction and arrangement of parts, as hereinafter fully described, illustrated in the drawings, and finally incorpo- 25 rated in the claims hereto appended In the accompanying drawings, Figure 1 is a longitudinal section taken through the hub ofthe driving-wheel of the bicycle. Fig. 2 is a detail perspective view of the outer face of 3o the hub-flange next to which the improved brake is arranged. Fig. 3 is a similar view of the inner face of the sprocket-rim. Fig. 4 is a detail view of the retracting-spring which moves-the sprocket-rim inward.

Similar numerals of reference designate corresponding parts in the several figures of the drawings.

The invention herein contemplated is shown in the drawings and will be described herein 4o as applied to the driving-wheel of an ordinary bicycle of the safety pattern; but it will be apparent that the present improvements are susceptible of other adaptations and that numerous changes in the form, proportion, and

45 minor details of construction may be resorted to without departing from the spirit or sacriiicing any of the advantages of the invention. Owing to the liability of the ordinary forms of brakes used upon bicycles and operating 5o against the tire to burn or abrade and otherwise injure the said tire, brakes have in a Patent No. 627,934, dated June 27, 1899. A

Serial No. 583,558. (No model.)

great majorityV of cases been dispensed with entirely, to the danger and risk, however, of the rider. The present invention aims to vprovide a brake 'which will/exert its restraining force at the hub of the wheel and which may be conveniently operated or thrown into action by voluntary or involuntary back-pedaling.

Proceeding now to the details of construction, 1 designates the hub of the driving-o wheel of a bicycle, one of the flanges of which' upon that side of the wheel upon which the chain is used is provided upon its outer face with a series of segmental cam projections 2, having outer inclined faces or edges 3 and inner or undercut inclined faces or edges 4, extending inward from the projecting ends or extremities of the cam projections and terminating in an adrupt shoulder 5. These segmental cam projections are arranged in the arc of the same circle andas near the periphery of the hub-flange as practicable. Vithin the cam projections is an outwardlyprojecting annular flange 6 concentric with the bore of the hub and with the arc in which the cam projections lie. This iiange 6 receives the sprocket-rim 7 and serves asabearing upon which said rim may be partiallyro tated, said sprocket-rim comprising an inside annular flange 8, forming its hub and sur rounding and bearing upon the flange 6 of the hub of the wheel, and an outer peripheral flange projecting upon both sides of the web portion and having the sprocket-teeth 8a thereon. Between the inner and outer iian ges of the sprocket-rim, which are spaced apart, are arranged cams 9, which are formed similarly to the cam projections 2 of the wheelhub, with inclined edges or faces 10, which correspond to and move against the edges or faces 3, above referred to, and with undercut inclined edges or faces 11, which registerwitli the corresponding edges or faces 4of thecam projections 2. The cams 9 terminate at the inner portions of their undercut edges or faces vin abrupt shoulders 12, which correspond to and cooperate with the shoulders 5 of the cam projections 2 to prevent the forward rotation of the sprocket-rim without causing the latter to take up and impart a corresponding rotation to the driving-wheel. A retracting-spring IOO large as the sprocket-rim will permit.

13 is'arranged between the Harige 7 of the sprocket-rimand the cam projections 2 and cams 9, said spring extending a greater portion of the distance around the axis of the hub and having one of its terminals deflected inward and engaged in a socket 14 in the wheel-hub and its other terminal deiiected outward and engaged in a socket or perforation 15 in the web of the sprocket-rim. The oflice of this spring is to hold the sprocketrim and wheel-hub in such relation that the shoulders and 12 arein engagement. Upon resisting the forward rotation of the sprocketrim the cam projections on the wheel-h ub will operate against the cams of the sprocket-rim and move said rim laterally away from the hub-flange. Upon the cessation of this resistance the spring 13 will exert its force to rotate the sprcket-rim in the reverse Adirection,and thereupon the undercut edges or faces of thev cams and cam projections will coperate to return the sprocket-rim inward to its normal position.

The sprocket-rim is provided upon its outer face with a female cone 1G, of a diameter as The axle (indicated at 17) has fast thereon a male cone 18, which is thus held stationary while the female cone rotates with the wheel-hub. The cone 18 being held stationary and being incapable of lateral movement, when the cone 16 is moved laterally away from the wheelhub by means hereinabove described the in` clined or oblique surfaces of the two cones will be brought into close frictional engagement and produce a binding and wedging action, which offers a considerable resistance to the rotation of the driving-wheel, thus acting as a brake. The sprocket-rim is actuated or rotated either in a forward direction, or the rotation of such rim is resisted by the ordinary drivingchain ofthe machine. When rotated in a forward direction, the sprocket-rim takes up and rotates the driving-wheel, but when by back pedaling the rider voluntarilyT or involuntarily resists the forward rotation of the sprocket-rim the driving-wheel will through its impetus operate upon the sprocket-rim and force the same laterally into binding engagement with the stationary cone.

The construction above described affords a simple, compact, and powerful brake, the presence of which on a machine is not noticeable and which will be thrown into action by even the involuntary back pressure upon the pedals on the part of the rider.

The hub-flange is provided with a threaded opening 19 and the sprocket-rim is provided in its web with an opening 20, through which a screw 2l may be passed into engagement with the threaded opening in the hub-liange for the purpose of locking the spoke-rim to the hub when it is not desired to use the brake. In order to facilitate the insertion of the screw for locking the spoke-rim, the stationary cone 18 also has an opening through which the screw 21 may be passed into and through the corresponding opening in the sprocket-rim.

The part 18 may be considered a stationary brake of circular form, and the part 16 a circular brake-shoe which is concentric with and movable toward and from the said circular brake, according to the relative rotation of the driving-wheel and driving means. The coacting cams 11 and 4 have their terminals disposed to abn t and li mit the relative forward turning of the driving means or sprocketwheel 7, whereby the jamming of the clutch elements 11 and 4 is obviated, thereby providing for their quick release when turning the driving means backward, asnpon back pedaling, so that the brake may be instantly set.

Having thus described the invention, what is claimed as new ist i 1. In combination, a wheel-hub, a brake member rigid with the axle, a loosely-mounted positively-driven part or rim having a brake member, cooperating camshaving their complementary parts attached to the wheelhub and driven part to positively hold the said brake members separated under normal conditions, and other cooperating cams inversely disposed to the first-mentionedicams and carried by the wheel-hub and driven part to force the brake members together `upon relatively reversing the direction of movement of the wheel and the said positivelydriven part, su bstantially as set forth.

2. The combination with a wheel-hub having segmental cam projections thereon, said cam projections being formed withl undercut inclined edges or faces, of a friction device fast on the stationary axle, a sprocket-rim connected loosely to the wheel-hub and pro.- vided with cams having undercut inclined edges or faces which cooperate with the corresponding edges or faces of the cam projections on the wheel-hub, a retractng-spring located between the sprocket-rim and Wheelhub and extending around or partially around the axis upon which the hub revolves and connected to the hub and rim, and provision for effecting a relative rotary movement between the rim and wheel-hub, substantially as described. j

3. The combination with a wheel-hub, and a stationary aXle upon ywhich the same is mounted, of a stationary friction device fast on the axle, a sprocket-rim "mount-ed' loosely between said stationary friction device and the wheel-hub, and also provided with a friction-surface adapted to cooperate with the aforesaid stationary friction device, interlocking cams on the adjacent faces of the wheel-hub and sprocket-rim respectively, whereby the sprocket-rim will be moved laterally upon the wheel-hub upon back-pedaling, and a vspring for actuating the sprocket to hold its clutch members normally in engagement with the hub, substantially as set forth.

4. r1`he combination with the wheel-hub,

IOO

IIO

. ner concentric with the axis ot' the wheel, a-

and the Stationary axle on which the same is mounted, of a stationary friction device fast on the axle, a sprocket-rim mounted loosely between the wheel-hub and friction device and provided lwith the friction-surface for engaging the latter, and m-eans for moving the sprocket-rim laterally into engagement with the friction device, the said wheel-hub and the sprocket-rim being provided with open` ings which may be brought into alinement for adapting a locking screw or pin to be inserted therethrough, substantially as and for the purpose described. v

5. In a brake mechanism for bicycles and like vehicles, the combination of brake mem.- bers independently mounted, the one being relatively ixed, the other having connection with the driving mechanism and movable laterally toward and from the xed brake member, cooperating cams to hold the brake mechanism out of action when the bicycle and movable brake member are driven forward, and other cooperating cams to set the brake mechanism upon back-peclaling,substantially as described.

6. In a vehicle-brake, the combination with the driving-wheel and driving means, of a circular brake mounted in a stationary manbrake-shoe rotatable with the driving-wheel and having lateral movement relative thereto, K

provisions for setting the brake upon a relative backward movement of the driving means,and cams between the wheel and brakeshoe to positively unset the brake and adapted to interlock and sustain the propelling force upon relatively rotating the driving mechanism forward,'substantially as described.

7. In a vehicle-brake, the combination with the driving-wheel and driving means, of a circular brake mounted in a stationary manner concentric with the axis of the wheel, a

brake-shoe rotatable with the drivingfwheel and having lateral movement relative thereto, cooperating cams between the vwheel and brake-shoe for setting the latter upon a relative backward movement of the driving means, and other cams between the wheel and brake-shoe to positively unset the brake and adapted to interlock and sustain the propelling force upon relatively rotating the driving means forward, substantially as specified.

8. In a vehicle-brake, the combination with a driving-wheel and driving means, of a circular brake mounted in a stationary manner concentric with the axis of the wheel, a brakeshoe adapted to operate in connection with the circular brake and supported by the drivingwheel with provisions for rotary and lateral motion relatively thereto, means interposed between the wheel and the brake-shoe for producin g a relative movement to said parts parallel to the axis of the wheel under a forced rotary movement to either of said parts, a connection between the driving means and the brake-shoe whereby the latter is moved laterally away from the circular brake under the driving action of the driving means and into engagement with the said brake under the retarding. action of said means, and a spring for normally holding the brake-shoe away from the circular-brake and assisting the driving means in its driving operation encircling theaxis of the wheel and having one end connected with it-s hub and the other with the brake-shoe, substantially in the manner and for the purpose specified.

In testimony that I claim the foregoing as my own I have hereto afiixed my signature in the presence of two witnesses.

CHARLES KNAFFL. Witnesses E. B. PENNINGTON, F. H. VALENTINE. 

